Method of immobilizing toxic waste materials and resultant products

Abstract

A method of immobilizing toxic waste material slurries is disclosed wherein aggregates are formed containing the toxic waste and the aggregates admixed with and embedded in a sulfur cement to form a concrete shape. Novel aggregates and mortar, and concrete products containing such aggregates embedded in a sulfur cement are also disclosed,

What is claimed is: 
     
       1. A method of immobilizing toxic waste material slurries comprising: (a) forming a cured aggregate by: (i) admixing a pozzolana, a calcium hydroxide-containing material, hydrothermal cement reactant, hydraulic cement, and said toxic waste material slurry with additional liquid, if required, to form a mixture of moldable consistency;   (ii) molding the mixture into a shape;   (iii) curing the shape; and   (iv) forming the cured shape into aggregates;     (b) admixing the aggregate with a molten sulfur cement, a pozzolana, and sand to form a mortar having the cured aggregate imbedded in the sulfur cement; and   (c) hardening the mixture into a solid mass.   
     
     
       2. The method of claim 1 in which a strong calcitic or siliceous aggregate is admixed with the cured aggregate, sulfur cement, pozzolana, and sand to form a concrete. 
     
     
       3. The method of claim 1 wherein the hydraulic cement is added to the admixture after the other components have first been thoroughly wetted and blended. 
     
     
       4. The method of claim 2 wherein the hydraulic cement is added to the admixture after the other components have first been thoroughly wetted and blended. 
     
     
       5. The method of claim 1 wherein said pozzolana is Class F fly ash, said calcium hydroxide-containing material is a lime; said hydrothermal cement reactant is zinc oxide, aluminum oxide, or a mixture thereof with anhydrous sodium silicate; said hydraulic cement is a Portland cement, calcium aluminate cement, plaster of paris, or a mixture thereof; and said sulfur cement is the reaction product of sulfur and a hydrocarbon. 
     
     
       6. The method of claim 2 wherein said pozzolana is a Class F fly ash, said calcium hydroxide-containing material is a lime; said hydrothermal cement reactant is zinc oxide, aluminum oxide, or a mixture thereof with anhydrous sodium silicate; said hydraulic cement is a Portland cement, calcium aluminate cement, plaster of paris, or a mixture thereof; and said sulfur cement is the reaction product of sulfur and a hydrocarbon. 
     
     
       7. The method of claim 5 wherein the proportions of components used to form the moldable mixture is:   ______________________________________                                    
                  Parts by Weight                                         
______________________________________                                    
Toxic Waste Material                                                      
                    20-40                                                 
Pozzolanic Cement    55-110                                               
Hydrothermal Cement Reactant                                              
                    2-5                                                   
Anhydrous Sodium Silicate                                                 
                    10-30                                                 
Hydraulic Cement    10-20                                                 
Water                30-40.                                               
______________________________________                                    
     
     
     
       8. The method of claim 6 wherein the proportions of components used to form the moldable mixture is:   ______________________________________                                    
                  Parts by Weight                                         
______________________________________                                    
Toxic Waste Material                                                      
                    20-40                                                 
Pozzolanic Cement    55-110                                               
Hydrothermal Cement Reactant                                              
                    2-5                                                   
Anhydrous Sodium Silicate                                                 
                    10-30                                                 
Hydraulic Cement    10-20                                                 
Water                30-40.                                               
______________________________________                                    
     
     
     
       9. An immobilized toxic waste-containing material product comprising shaped, cured aggregates comprising a pozzolanic cement, hydrothermal cement reactant hydraulic cement and toxic waste material imbedded in a sulfur cement. 
     
     
       10. The product of claim 9, wherein said pozzolana is Class F fly ash, said calcium hydroxide-containing material is a lime; said hydrothermal cement reactant is zinc oxide, aluminum oxide, or a mixture thereof with anhydrous sodium silicate; said hydraulic cement is a Portland cement, calcium aluminate cement, plaster of paris, or a mixture thereof; and said sulfur cement is the reaction product of sulfur and a hydrocarbon. 
     
     
       11. The product of claim 10, wherein the proportions are as follows:   ______________________________________                                    
                Parts by Weight                                           
______________________________________                                    
Cured Aggregate   0.35-1                                                  
Modified Sulfur Cement                                                    
                   0.1-1.5.                                               
______________________________________                                    
     
     
     
       12. The product of claim 10 in the form of a slab, cinder block, or brick. 
     
     
       13. The product of claim 11 in the form of a slab, cinder block, or brick. 
     
     
       14. The product of claim 9 including a pozzolana and sand admixed with the cured aggregates and sulfur cement. 
     
     
       15. The product of claim 14 in which a strong calcitic or siliceous aggregate is also admixed with the cured aggregates and sulfur cement. 
     
     
       16. An immobilized toxic waste material aggregate comprising a cured composition comprising a pozzolanic cement, hydrothermal cement reactant, hydraulic cement, and toxic waste material. 
     
     
       17. The aggregate of claim 16, wherein the proportions are as follows:   ______________________________________                                    
                  Parts by Weight                                         
______________________________________                                    
Toxic Waste Material                                                      
                    20-40                                                 
Pozzolanic Cement    55-110                                               
Hydrothermal Cement Reactant                                              
                    2-5                                                   
Anhydrous Sodium Silicate                                                 
                    10-30                                                 
Hydraulic Cement    10-20                                                 
Water                15-30.                                               
______________________________________                                    
     
     
     
       18. The aggregate of claim 17, wherein the aggregate particles range in size from about 1/4 to 1/2 inch in diameter.